This invention relates to final molds for forming composite parts, to intermediate molds (i.e., splashes) for forming final molds, and to master molds (i.e., mock-ups) for forming intermediate molds, and more particularly to any of the three molds that is a reusable, one-piece mold that is selectively stiffened or flexible to facilitate the formation and removal of another mold or a composite part from the mold.
Conventional prior art molding practices used for fabricating finished composite parts having complex shapes often require a final mold comprising a unitary part or a plurality of segments. This practice is common, for example, when fabricating finished composite parts for an aircraft or rotorcraft, such as the nacelle for an engine. It is also used in fabricating the intermediate tooling components, such as mock-up and splash molds, that are used in the fabrication of the final mold. That is, it is known to first fabricate a master mold, termed a "mock-up", that may be a "male" part having surface contour features of the ultimate part to be formed (e.g., engine nacelle). Next is typically formed from the mock-up an intermediate mold, termed a "splash" which may be a "female" mold. Then, the final mold is formed from the splash. It is from this final "male" mold that the engine nacelle or other part is fabricated. It is to be understood throughout the discussion and teachings herein, including the claims, that the term "mold" may refer to not only the final mold, but also to the mock-up and intermediate ("splash") molds. These mock-up and splash molds may also be referred to together herein as intermediate tooling. Also, the mock-up, splash and final molds may be either "female" or "male" molds, depending upon the application.
Nevertheless, after the composite part or shell of the fabricated mold (i.e., the splash or final mold) that is formed on a shell of the mold has cured, the unitary mold or mold segments are removed to free the composite part or fabricated mold therefrom. As a result of this process, the unitary mold or mold segments are usually damaged. This is because the composite part or shell of the fabricated mold typically has a complex shape; i.e., one with regions having sharply defined peaks and/or valleys. Such complex shape makes it difficult to separate the mold from the composite part or fabricated mold without damaging the mold. It is also because the prior art molds were entirely rigid, such rigidity being required to properly support the composite part or fabricated mold during its formation. On the other hand, a mold that was flexible at all times would not properly support the composite part or fabricated mold. Thus, the prior art practice of using rigid unitary or segmented molds is costly and comparatively labor intensive.
Heretofore, no known reusable unitary molding apparatus has been devised that facilitates the formation of composite parts or fabricated molds having complex shapes and their removal therefrom.
Accordingly, it is a primary object of the present invention to provide reusable, selectively-flexible, selectively-rigid, one-piece, mock-up, splash and final molds for forming, respectively, the corresponding splash and final molds and finished composite parts.
It is a general object of the present invention to provide such a reusable, one-piece mold that saves considerable amounts of labor and parts costs as compared to prior art conventional rigid unitary or segmented molds that would be damaged or would not maintain vacuum integrity during part removal from the mold.
It is a further object of the present invention to provide a unitary final mold for fabricating finished composite parts having complex shapes, the final mold being selectively-flexible to allow it to be removed from the finished composite part without damaging the final mold.
It is yet another object of the present invention to provide a unitary master mold (e.g., a mock-up) for fabricating a unitary intermediate mold (e.g., a splash), or to provide a unitary splash for fabricating a final mold, the mock-up and splash molds being selectively flexible to facilitate removal of the corresponding fabricated mold therefrom without damaging the mock-up or splash molds.
The above and other objects and advantages of this invention will become more readily apparent when the following description is read in conjunction with the accompanying drawings.